The present disclosure is related to controlling a hierarchical storage including a solid-state disk storage, a hard disk storage, and a tape storage.
Typically, hard disk storage has been considered as a major storage device to store and manage massive contents regardless of an inquiry frequency and a required minimum transmission rate of each content. However, a hard disk has latency not fast enough to satisfy consumers of multimedia contents (e.g., multimedia streaming service). A solid state disk has been used to reduce such latency to access a target content and to quickly provide the target content to a consumer. However, there is a limitation to use a solid state disk to store massive amount of contents due to high cost.